In our news wrap Thursday, at least 47 people were killed and more than 100 wounded in Libya by a truck bomb targeting a police training center with hundreds of recruits. Also, dozens of Saudi airstrikes hit targets in Yemen's capital, including the presidential palace and a rebel military base.

Read the Full Transcript

GWEN IFILL:

Call it the great fall. An explosive new sell-off hit the Chinese market today, and routed stocks around the world. On Wall Street, the Dow Jones industrial average lost 392 points to close at 16514. The Nasdaq fell 146 points, and the S&P 500 dropped 47. We will look at what's going on in China right after the news summary.

And in the day's other news, a powerful truck bomb in Libya killed at least 47 people and wounded more than 100 others. The target was a police training center outside Tripoli, where hundreds of recruits had gathered. Cars lay crushed and strewn around the area after the blast. It was the country's worst bombing since the fall of Moammar Gadhafi in 2011 and it was quickly condemned.

MOHAMMAD ISMAIL, Spokesman, National Salvation Government (through interpreter): We confirm that we are totally committed to carrying out a full investigation and following developments and updates and providing full disclosure that deals with this cowardly terrorist act.

GWEN IFILL:

The government based in Tripoli is an Islamist regime. A rival government operates in Eastern Libya, along with various armed factions.

In Yemen, dozens of Saudi airstrikes hit the capital city in the heaviest bombardment yet. The Saudis and other Sunni Arab states are supporting Yemen's president against Shiite rebels. Today's attacks hit the presidential palace in Sanaa and a rebel military base. Meanwhile, loyalist forces also landed at a key port overnight, opening a new front. Iran claimed its embassy in Sanaa was hit by the airstrikes, but there was no visible damage.

Paris spent a tense anniversary today, one year since Islamist gunmen attacked the satirical newspaper Charlie Hebdo, killing 11 people. The city was already on edge when an apparent suicide bomber, with a note referencing the Islamic State group, confronted police.

Alex Thomson of Independent Television News reports from Paris.

ALEX THOMSON:

It's around midday in the Gare du Nord in Central Paris, and a young man carrying a butchers hatchet, shouting Allahu akbar and wearing what looks like an explosive belt approaches a small police station.

MAN (through interpreter):

I heard gunshots, four, I think. It's just across the street from the school, next to the police station, where there's a kindergarten.

WOMAN (through interpreter):

Usually, I see this on the television. And it's true, it's shocking to see this unfolding live.

ALEX THOMSON:

It's a busy area. People quickly surrounded the body before it was eventually stretchered away, but only after a remote controlled approach to what was initially assumed to be a real suicide belt device.

We may well never know what this man's motivations were, nor if he had any real connection with I.S., or Da'esh, but after the events in recent months, not just in Paris, but across Europe, anybody approaching armed officers with a butcher's hatchet, apparent signs of an explosive device, and shouting allahu Akbar, is signing their own death warrant.

All of this a year to the day from the massacre across town at the satirical magazine Charlie Hebdo — the journalists killed there remembered today. And whether this man actually had any connection to I.S., the president of France spoke today as if the incident had been masterminded in Raqqa.

PRESIDENT FRANCOIS HOLLANDE, France (through interpreter):

Inside France, we are tackling it by hunting down terrorists, dismantling networks, drying up sources of financing, and by blocking the propaganda of radicalization.

The Charlie Hebdo killings last January were followed by the attacks in November that claimed another 130 lives.

South Korea is firing up its cross-border propaganda broadcasts against the North again. Today's announcement came a day after North Korea tested what it said was a hydrogen bomb. The South's earlier broadcasts ended in August in a bid to ease tensions with the communist North. They're due to resume tomorrow, the birthday of North Korean leader Kim Jong-un.

Back in this country, there's word that efforts to extend health insurance coverage to all Americans stalled in 2015. A closely watched survey out today finds nearly 12 percent of U.S. adults still lacked health coverage at the end of the year. The Gallup-Healthways Well-Being Index says that was virtually unchanged from 12 months earlier.

And 2015 officially goes down as the second warmest year in the United States since they started keeping records 121 years ago. The National Oceanic and Atmospheric Administration reports the average temperature was 54.4 degrees. That's about one degree shy of the record, set in 2012.